PUGET SOUND CRUSTACEN. 279 



of finger-like processes where our specimens show three. The 

 first pair, Walz states, develops into the mandibles, and he 

 suggests that the second pair corresponds to one of the pairs of 

 maxillae which by fusion give rise to the lower lip (/. c\ p. 14). 

 The latter part of his suggestion appears hardly probable. The 

 minute lobes behind the upper lip are not referred to in the text. 



The figure which Giard and Bonnier give of the mouth 

 parts of an embryo of Cancidon miser (Contr. a 1' etude d. Bo- 

 pyriens, PI. IX, f. 13), though taken from an earlier stage, cor- 

 responds fairly well with our specimens. Two small lobes close 

 to each other, lettered lb in their figure, are evidently the same 

 as those which we have lettered /. The figure does not seem 

 to be fully discussed anywhere in the text of the monograph, 

 but in the explanation of the plate the interpretation of the 

 letters is given as " premiere paire d' appendices buccaux (labre)." 

 In their figure of a newly-hatched embryo of Portunion Koss- 

 vianni {op. cit., PI. X, f i), a pair of appendages exactly similar 

 in shape and position are lettered as mandibles. In Cancrion 

 three pairs of appendages follow upon those just discussed. Of 

 these the first two pairs are simple and are interpreted as man- 

 dibles and first maxillae, while the third pair are biramous and 

 are identified as the maxillipeds. In Portimion only two pairs of 

 appendages are present in the corresponding position, both 

 simple and lettered as first maxillae and maxillipeds. 



We cannot attempt to reconcile these seemingly contradictory 

 accounts of species which we have not studied, and shall only 

 indicate what seems to be the most probable interpretation of 

 the specimens before us. The rudiments which we have let- 

 tered / seem, from their position close together in the median 

 line, to be the paragnatha which afterwards fuse to form the lower 

 lip. This leaves three pairs of rudiments to be allotted between 

 the four pairs of appendages from mandibles to maxillipeds, 

 and we may assume one of the pairs of maxillae to be missing 

 (probably the first pair, which appears to be absent in the adults 

 of both sexes). On the other hand, it is possible that the rudi- 

 ments / may, in spite of their small size and median position, 

 represent the mandibles, in which case the other appendages 



